GitLab

- LLVM now uses C++11, so need to use LLVM_OVERRIDE anymore.
- Small changes in Clang interfaces for flags and FrontendFactory
  instantiation.
- clang-format-diff.py works slightly differently now, so update the
  run_tool.py wrapper to invoke it correctly.
- Delete tools that are no longer needed.

BUG=
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/448693003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287841 0039d316-1c4b-4281-b951-d872f2087c98